`TestClient` 是基于 [HTTPX](https://www.python-httpx.org) 的。幸运的是，我们可以直接使用它来测试 API。

## 示例 { #example }

举个简单的例子，让我们来看一个与[更大的应用](../tutorial/bigger-applications.md)和[测试](../tutorial/testing.md)中描述的类似文件结构：

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

文件 `main.py` 将包含:

### Archivo de aplicación **FastAPI** { #fastapi-app-file }

Digamos que tienes una estructura de archivos como se describe en [Aplicaciones Más Grandes](bigger-applications.md):

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

En el archivo `main.py` tienes tu aplicación de **FastAPI**:


{* ../../docs_src/app_testing/app_a_py310/main.py *}

### Файл приложения **FastAPI** { #fastapi-app-file }

Допустим, структура файлов Вашего приложения похожа на ту, что описана на странице [Более крупные приложения](bigger-applications.md):

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

В файле `main.py` находится Ваше приложение **FastAPI**:


{* ../../docs_src/app_testing/app_a_py310/main.py *}

   * and {@link java.util.concurrent.CompletableFuture#handleAsync} when used along with {@link
   * #transform}.
   *
   * @param exceptionType the exception type that triggers use of {@code fallback}. The exception
   *     type is matched against the input's exception. "The input's exception" means the cause of

### Fichier d’application **FastAPI** { #fastapi-app-file }

Supposons que vous ayez une structure de fichiers comme décrit dans [Applications plus grandes](bigger-applications.md) :

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

Dans le fichier `main.py`, vous avez votre application **FastAPI** :

`TestClient`는 [HTTPX](https://www.python-httpx.org)를 기반으로 하며, 다행히 HTTPX를 직접 사용해 API를 테스트할 수 있습니다.

## 예시 { #example }

간단한 예시로, [더 큰 애플리케이션](../tutorial/bigger-applications.md)과 [테스트](../tutorial/testing.md)에서 설명한 것과 비슷한 파일 구조를 살펴보겠습니다:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

`main.py` 파일은 다음과 같습니다:

Und Ihre **FastAPI**-Anwendung könnte auch aus mehreren Dateien/Modulen, usw. bestehen.

### **FastAPI** Anwendungsdatei { #fastapi-app-file }

Nehmen wir an, Sie haben eine Dateistruktur wie in [Größere Anwendungen](bigger-applications.md) beschrieben:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

In der Datei `main.py` haben Sie Ihre **FastAPI**-Anwendung:

The response object will also have autocompletion:

<img src="/img/tutorial/generate-clients/image05.png">

## FastAPI App with Tags { #fastapi-app-with-tags }

In many cases, your FastAPI app will be bigger, and you will probably use tags to separate different groups of *path operations*.

For example, you could have a section for **items** and another section for **users**, and they could be separated by tags:

The client will get a **500 Internal Server Error** for that request, but the application will continue working for the next requests instead of just crashing completely.

### Bigger Errors - Crashes { #bigger-errors-crashes }

Nevertheless, there might be cases where we write some code that **crashes the entire application** making Uvicorn and Python crash. 💥

// lineTooLong is generated as chunk header is bigger than 4KiB.
var errLineTooLong = errors.New("header line too long")

// malformed encoding is generated when chunk header is wrongly formed.
var errMalformedEncoding = errors.New("malformed chunked encoding")

// chunk is considered too big if its bigger than > 16MiB.
var errChunkTooBig = errors.New("chunk too big: choose chunk size <= 16MiB")